Weigh bar switch arrangement for automatic ice maker

ABSTRACT

A weigh switch to stop production of an automatic ice maker whenever the ice collecting bin is either filled with ice pieces or removed from its carrier means. An electrically conductive bin weigh bar is pivoted on a terminal post to provide a first lever arm loaded by the carrier means and a second counterbalancing lever arm which pivots the bin weigh bar from a first open circuit position to a second ice maker energizing position electrically contacting an overlying conductive pivoted ice weigh bar when the bin is inserted in the carrier means and the combined weight of the bin and its contents is below a predetermined amount. In response to the weight of a filled bin, the bin and ice weigh bars are pivoted in unison to a third open circuit position thereby terminating the production of ice pieces.

United States Patent 11 1 l [111 3,751,939

Bright 1 Aug. 14, 1973 WEIGH BAR SWITCH ARRANGEMENT FOR PrimaryExaminerWilliam E. Wayner AUTOMATIC ICE MAKER Attorney-William S.Pettigrew, Edward P. Barthel [75] Inventor: James A. Bright, Dayton,Ohio et [73] Assignee: General Motors Corporation, [57] ABSTRACTDetroit, Mich. A weigh switch to stop production of an automatic weFlledi 1972 maker whenever the ice collecting bin is either filled [21]APPL No; 302,743 with ice pieces or removed from its carrier means. Anelectrically conductive bin weigh bar is pivoted on a terminal post toprovide a first lever arm loaded by the [52] US. Cl. 62/137, 222/58carrier means and a second counterbalancing lever arm [51] Int. Cl. F255/18 which pivots the bin weigh bar from a first open circuit Fieldsfll'ch 222/58 position to a second ice maker energizing positionelectrically contacting an overlying conductive pivoted ice RefflfllcesCited weigh bar when the bin is inserted in the carrier means UNITEDSTATES PATENTS and the combined weight of the bin and its contents is3,540,227 11/1970 Eyman, Jr. et al 62/137 belew a predeterminedammmtespense the 3,601,145 8/1971 Eyman, Jr 62/137 x Weight Of a filledbin, the bin and ice Weigh bars are P oted in unison to a third opencircuit position thereby terminating the production of ice pieces.

4 Claims, 7 Drawing Figures WEIGII BAR SWITCH ARRANGEMENT FOR AUTOMATICICE MAKER This invention relates to automatic ice makers for domesticrefrigerators and in particular to a counterbalanced weigh bar electricswitching system for automatically stopping the production of ice pieceswhenever the collecting bin is either filled with ice pieces to apreselected load or the bin is dislodged from the ice maker.

In one form of improved automatic ice maker disclosedin the Eyman,Jr.,et al. U. S. Pat. No. 3,540,227, owned bythe assignee of the instantinvention, a mold is provided with an ejecting means for transferringformed; ice pieces to a subjacent collecting bin. In the Eyman patent acommutator timing gear is provided together with, a mold temperaturesensing thermostat which have cooperating spring contacts forcontrolling the filling, freezing and ejecting cycles of the ice maker.One of the commutator contacts is actuated by a pivotal ice collectingbin supporting carrier by means of a cooperating weak and strong coilsprings arrangement stopping the production of ice pieces whenever thebin is disloged or removed from its inserted position or when the bin isloaded with ice pieces to a preselected weight. Such an arrangementrequires the individual calibration of each icemaker because of theinherent variability of coil springs, thus materially increasing thecost. of manufacture of each ice maker unit.

It is an object of the present invention to provide an automatic icemaker having an improved means for sensing the'load condition of an icepiece collecting bin pivotally supported from a first lever arm of anelectrically conductive pivoted bin weigh bar by knife edge meanswherein the bin weigh bar is rotated about its fulcrummed support to afirst open circuit position by a counterbalancing second lever arm whenthe bin is dislodged from the ice maker, and wherein the bin weigh-baris rotated to a second circuit closing position with, the second leverarm in electrical contact with an overlying ice weigh bar under the loadof a positioned empty or partially filled ice collectingbin and whereinthe second lever arm pivots the ice weigh bar in unison therewith to athird open circuit position in response to the weight of a predeterminedloadof ice pieces in the bin thus automatically stopping the operationof the ice maker.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIG. I: is an irregular vertical-sectional 'view through a refrigeratorembodying an air cooled automatic ice maker illustrating the invention;

FIG. 2 is an enlarged fragmentary vertical sectional view of the icemaker of FIG. 1 showing the drive and control mechanism;

FIG. 3is a sectional view taken along line 3-3 of FIG. 1;

FIG. ,41is an enlarged partial horizontal sectionalview takenialong line4-4 of. FIG. 1;

RIG. 5". is. a fragmentary vertical elevational view partly insectiontaken along line 5-5 ofFIG. 3;

FIG. 6 isa view of the balance beam weigh bar showingdimensional ratioof its lever. arms;

FIG; 7zis.a;.schematic wiring diagram.

Referring now to the drawings and more particularly to FIG. 1, there isshown the upper portion of a frostfree type of household refrigerator 20with an upper below-freezing compartment 22 enclosed by an insulateddoor 24 and a lower above-freezing compartment 26 enclosed by a lowerinsulated door 28. These compartments are surrounded by the insulatedside, top, bottom and rear walls 30 separated by horizontal insulatedwall 32 containing an evaporator compartment 34 provided with finnedevaporator 36 having vertical fins extending from the front to the rearof the compartment 34. Evaporator compartment 34 is provided I with aninlet 38 at the front communicating with the front of the below-freezingcompartment 22 and additional inlets (not shown) communicating with thetop of the above-freezing compartment 26. At the rear, the compartment34 connects with a shroud 40 communicating with the entrance of acentrifugal fan 42 which is driven by an electric motor 44 housed in arear wall 30 of the cabinet. The cooling arrangement for thecompartments may be similar to that shown in U.S. Pat. No. 3,359,750issued Dec. 26, 1967, or U.S. Pat. No. 3,310,957 issued Mar. 28, 1967,owned by the asignee of the present application and which may bereferred to for further details of construction of the refrigerator.

The fan 42 is provided with an upwardly extending discharge duct 46having a distributor 48 at the top which distributes the discharge ofair through the below-freezing compartment 22. Evaporator 36 ismaintained at suitable below-freezing temperatures such as 5 to -15 F.to maintain the compartment 22 at the temperature of 0 F. or below.

For providing special cooling for the automatic freezer the distributor48 is provided with a laterally extending discharge duct 50 extendingalong the intersection of the rear and top walls. Behind automatic icemaker 52 the laterally extending duct 50 is provided with wide dischargenozzle 54 which discharges the cold air directly onto the top of the icemaker 52 and particularly onto the top of its ice piece forming mold 56.

As seen in FIGS. 1 and 2 the mold 56 is provided with two rows ofpockets 58 containing four pockets in each row and has an upwardlyflanged rim 60 extending around the short and long sides thereof. Themold 56 of the ice maker is supplied with water or any other liq uid tobe frozen from a pressure water system or other liquid under pressure toa solenoid control valve 62 which controls the flow of water throughpipe 64 extending through the insulation of the top wall to a suitabledischarge device 66 in the top wall of the belowfreezing compartment 22above the front pockets 58 of the mold 56. The ice maker 52 is providedwith a wide U-shaped frame 68 which surrounds the mold 56 and isfastened to the adjacent side wall of the freezing compartment 22 bysuitable screws. Below the frame 68 is a rectangular bin carrier 70having, adjacent the rear, a pair of upwardly extending projections 72positioned respectively adjacent the inner surfaces of the frame sidewalls and having outwardly directed pivot pins 74 extending throughaligned apertures in the side walls such that the carrier 70 is pivotedabout a horizontal axis. By virtue of this arrangement the weight of thebin and carrier biases the forward end of the carrier in a downwarddirection about the pivotal axis of pins 74.

As a result it will be appreciated that the rear portion of the carrier70 together with an inserted bin 78 is supported by the pivotal pins 74for movement about a substantially horizontal axis that is displacedrearwardly from the center of gravity of the carrier and bin while theforward portion of the carrier and bin is supported by suspension meansin the form of a weigh shaft or rod 243 displaced forwardly from thecenter of gravity of the carrier and bin. In the disclosed form of theinvention the axis of the support pins 74 is located approximately oneand three-quarters inches closer to the center of gravity of thecombined carrier and bin than the vertical axis of weigh rod 243. Thus,for example, if the combined weight of the bin and carrier is about 1.80pounds the weight will be distributed so that a downward pull or forceof about 0.70 pounds will be applied to the weigh rod 243 and a slightlylarger force of about 1.10 pounds will be applied to the pivotal pins74. By virtue of this arrangement the carrier and fully inserted bincreate an unbalance or moment such that the front end of the carriertends always to gravitate or pivot in a downward direction about theaxis of pins 74.

In the disclosed form of the invention the mold delivers eight icepieces into the bin, having a total weight of about one-third pound,during each harvest of the ice maker. Consequently, the bin load onweigh rod 243 is proportionally increased in stepped increments. A weighbar electrical switch arrangement to be described is designed to sense apercentage of the total weight of the carrier and filled bin appliedthereto by means of the downward pull on weigh rod 243 proportional to apredetermined number of ice harvesting cycles. In a manner to beexplained the final harvest of ice pieces discharged into the bin 78creates a cumulative load which overshoots the neutral balance conditionof the weigh switch by a predetermined amount to produce a triggeringdownward pull on weigh rod 243 to insure that the automatic ice makercontrol circuit is immediately opened.

It will be noted that the bin carrier 70 is provided with supportingledges 76 on its inner sides for slidably supporting the laterallyextending flanges 80 of the box-shaped bin 78 while the bin 78 isprovided with a double flange 82 at the front to serve as a handle.

A description of the ejection and control systems of the ice maker isunnecessary herein since they are described in the above-mentioned US.Pat. No. 3,540,227, the disclosure of which is incorporated herein byreferencev For accessibility all the mechanism and controls are locatedat the front of the freezer with the tray rotating and twistingmechansim disclosed in US Pat. No. 3,540,227, and the control systembeing located in the housing 127 while an electric driving motor 129 andthe wiring are located on the front face of wall or mounting plate 133.The housing 127 and plate 133 are preferably formed from suitableplastic material. Substantially the entire operating and controlmechanism are mounted upon the irregular plastic upright plate 133 whichcloses the housing 127 to form compartment 135. The front face of plate133 supports the drive motor 129 having its final drive shaft extendingthrough the dividing wall or electrical control plate 133 and providedwith a drive pinion 139 on the opposite side which continuously mesheswith a large driven gear 141. The large gear 141 has an apertured hub191 (FIG. rotatably mounted in a removable manner by a suitable snapretainer 192 on the inner shaft end of hexgon collar bolt 143. The outerthreaded end of bolt 143 extends through opening 144 in boss 145 on wall133 and is fixedly secured thereto by lock nut 147 and its collar 148.

The large gear 141 is recessed to receive and hold in position the thinbrass nickel plated commutator 193 which is shown bonded to the face ofthe gear 141 nearest the wall 133. As seen in FIG. 3 the commutator 193includes a fill projection or segment 195 cooperating with a springcontact and terminal member 197 to measure the till period by the timeperiod required for the fill projection or segment 195 to move past theupper end of the spring contact 197. The commutator 193 also includes adelay projection or segment 199 which cooperates with the delay or stopswitch arm 221 having a ball type spring contact end which normallyengages the delay and fill segments 199 and 195 of the commutator 193and during the remainder of the time contacts the plastic surface of thegear 141. The stop switch arm 221 is in electrical continuity withthreaded terminal post B which is in turn electrically connected toterminal I of thermostatic relay 283 via lead 222.

As seen in FIG. 4 the weigh rod 243 is vertically slidably mountedthrough the aperture 249 in the bottom of the upright dividing wall 133and projects through the bottom thereof and through a slot 245 in thefront cross member 248 of the bin carrier 70. The bottom of the weighrod 243 is provided with a C-shaped disc retainer 247 which is keyedthereto and which supports the front cross member 248 of the bin carrier70.

The weigh rod 243 has an enlarged cylindrical upper head portion 250integrally molded on the upper end thereof formed with a transverselyextending notched portion 251 having horizontally disposed opposed upperand lower surfaces in vertically spaced dimension to receive therein therelatively short lever arm 252 of an electrically conducting balancebeam or bin weigh bar 254 fulcrummed on wall 133 by pivot terminal postA below pivoted ice weigh bar 256. The bin weigh bar 254 which is inelectrical continuity with terminal post A is pivoted in a verticalplane to extend perpendicular to the axis of the post "A such that thebin weigh bar 254 is counterbalanced to its horizontal position.

As best seen in FIG. 6 the bin weigh bar is shown diagrammatically inits counterbalanced horizontal position such that its relatively shortlever arm 252, formed with an upwardly and outwardly tapered surfaceknife edge contact 255, designed to engage with a planar metal surfaceprovided by a U-shaped clip 258 which may be snapped into the weigh rodnotch 251. The weigh bar 254 has a relatively long lever arm 260functioning as a counterbalance whereby the beam 254 is unbalanced andtends to gravitate the long lever arm in a clockwise direction to afirst generally horizontal open circuit position in engagement with afirst stop boss 262. The distance L, shown in FIG. 6, between the uppermarginal edge 257 of the lever arm 260 and the fulcrummed pivot post Ais of the order of 15 times the relatively short lever arm 252 distanceX, between the knife-edge 255 and pivot post A." Thus, in the disclosedform the weigh bar 254 develops a ratio of about 15:1 for transmittingthe weight of the inserted bin vertically therethrough so as to bemultiplied thereby. For example, in the present embodiment the distanceL, is

of the order of 1.875 inches and the distance X is of the order of 0.125inches.

An' elongated electrically conductive ice weigh bar 256is pivoted onpivot pin 263 whose threaded end as seen in FIG. 5 is secured by nuts264 to wall 133. The pivot pin 263 of the ice weigh bar 256 ispositioned outboard of the bin weigh bar contact edge 257 and extendslengthwise in a direction opposite to the direction of the relativelylong lever arm 260.

The ice weigh bar 256 is of a length such that its free end 265 extendsoutboard of theknife edge 255 a sufficient distance such that the iceweigh bar 256 tends to gravitate in a downward counterclockwisedirection (FIG. 6) toward a horizontal closed circuit position spacedabove and generally parallel to the first or counterbalanced opencircuit position of the underlying bin weigh bar 254. In its closedcircuit position the ice weigh bar free end 265 is supported on a fixedelectrical contact in the form of threaded terminal post H having a pairof securing contact nuts 267 and 268 thereon between which spring switcharm 225 is retained inelectrical continuity with post H.

In operation the bin weigh bar 254 is designed so that with the bin 78outwardly displaced or removed'from the freezer the bar 254 is in itsgenerally horizontal dashed-line first open circuit position (FIG. 3)engaging first stop boss 262 such that its marginal edge 257 of longlever arm 260 is spaced in parallel fashion from the underside of thegenerally horizontal ice weigh bar 256. When the bin 78 is fullyinserted in carrier 70 the short lever arm 252 is rotated slightly in acounterclockwise direction from its overbalanced position (as viewed inFIG. 4) and the downward pivoting force on lever arm 252 will efiect anupward pivotal movement of lever arm 260 a proportionately greaterdistance to a second closed circuit position operative to provide anelectrical pathbetween marginal edge 257 and the underside (if the iceweigh bar 256 and as a result electrical continuity is establishedbetween post A, fixedcontact post H and spring switch contact arm 225having a rounded-nose contact 270 in continuous contact with thecommutator 193. j

The circuit for the ice maker, partially shown in the FIG. 7 schematic,is carried on the mounting plate 133 covering the housing 127. After themold has been filled with water the thermostatic switch 283 has amovable contact 302 which closes to its fixed terminal contact I on arising predetermined temperature, sensed by tube 285 at temperatures ofabout 19 Fgl" F., which means that there is no continuity via line 284from thermostat terminal contact III to post A through the weigh switchassembly, to post H, arm 225, commutator 193, am 279 of post D connectedto power line 290 via fixed spring contact arm 225 and commutator 193rendering the motor circuit incomplete. The ice bin 78 is empty and inposition in the carrier 70. When the ice pieces are frozen and thesensing tube 285 temperature drops to a predetermined temperature, whichin the disclosed form is about 16 F. i lF.,' the thermostat movablecontact 302 closes to fixed terminal contact Ill completing a circuit topost A, through the weigh switch bar's, terminal post H and fixedspringcontact 225, to post D connected to power line 290 completing a circuitto the motor 129 and the other side of the line 291. This beginsthe'harvest cycle. As commutator 193 is attached to the large gear 141,which is driven directly off of the motor pinion gear I39, whenever theunidirectional motor 129 runs, the commutator 193 must also rotate in aclockwise direction as viewed in FIG. 3.

As the commutator continues to advance until the holding switch 267connected to terminal post C is closed by moving past notch 269 whichcompletes the motor 129 circuit directly to the commutator 193. It is atthis point that the mold 56 begins its first clockwise twist and thecircuit cannot be interrupted by the weigh switch bars until the firsttwist has been completed and the tray has been returned to a normalhorizontal position and on past to a position just before the ice piecesfall from the mold 78.

Before the holding switch 267 opens the delay switch 221 will close.When the holding switch 267 has opened the only way the motor 129 can beenergized to complete the ice making cycle is for the thermostat sensingtube 285 to warm up to the predetermined 19 F. temperature causingmovable contact 302 to close to terminal contact I." The holding switch267 opens,

when the mold has been rotated through approximately a 45 angle, withthe notch 271 beneath the adjacent end of the spring contact 267 to stopthe ice maker at a desirable time and not when the mold is under atwist. Terminal F of the fill switch 197 is closed when its end engagesfill projection 195, completing the circuit from the commutator 193 tothe solenoid 306 (FIG. 7) of the fill valve 62. The holding switch 267of post C is closed via line 289 from terminal II to preventinterruption of the motor circuit during the Fill interval which isabout a 12 second period.

A positive temperature coefficient thermistor heater 307 is positionedadjacent the bellows 284 of the thermostatic switch 283 and provides asmall amount of heat to insure the operating temperatures of thethermostat are controlled by the temperature of the thermostat sensingtube or bulb 285 rather than being controlled by the temperature of thecasing of the bellows 284. The heater 307 is connected by line 294 tospring contact 279 of line post D continuously closed to the commutator193 and line 295 to line post E.

Reference is now made to FIG. 6 which diagrammatically illustrates theweigh bar assembly system which comprises the bin weigh bar 254supported on the fixed pivot pin A for pivotal movement or displacementin response to the ice storage bin forces acting on the bar 254. In thedisclosed form the forces include the variable force f, whichincludes-theforce of the bin carrier (F and the force of an empty orpartially full ice collecting bin 78 (Ft) while the force of the carrierand a full bin of ice pieces if F,. With the relationships states thefollowing force conditions exist.

1. For f F F, no electrical continuity between A and H.

2. For F F f, F electrical continuity exists between A and H.

3. For f F, no electrical continuity exists between A and H.

Relationship (I) demonstrates that when the bin 78 is removed from thecarrier 70 the weight of the carrier alone producing variable force f isinsufficient to pivot bin weigh bar 254 in a counterclockwise direction(as viewed in FIG. 6) from its horizontal overbalanced position engagingstop boss 262. In the disclosed form the effective counterclockwisemoment acting on the bin weigh bar 254 because of the variable force f,is exerted at knife edge 255 on the relatively short first lever arm252, whose length X, is of the order of 0.125 inches.

The weight W, of the bin weigh bar 254 acts as a counterweight throughits center of gravity (c.g.) with an effective moment arm Y, of about1.051 inches to create a total effective clockwise unbalanced moment onthe bin weigh bar 254 in opposition to the counterclockwise momentcreated by the bin carrier 70 with the bin 78 removed to prevent pivotalmovement of the bin weigh bar 254 from its horizontal static equilibriumposition engaging limit stop 262.

Relationship (2) demonstrates that when the bin 78 is inserted in thecarrier 70 the variable force f, is equal to or greater than apredetermined load, which is about 0.7 pounds in the form shown, andwill create a moment sufficient to overcome the constant load W, topivot the bin weigh bar 254 in a counterclockwise direction causing edge257 to come to a second static position in contact with the underside ofbeam lever 256 and establish electrical continuity between terminals Aand H. In this statically balanced or neutral position, shown in solidlines FIG. 3, the bin weigh bar 254 and ice weigh bar 256 act as acompound weigh bar lever system with variable equal and opposite force fbeing exerted on the bin weigh bar 254 through a moment arm L, and theice weigh bar 256 through moment arm X2.

The relationship (3) demonstrates that when the total moment produced onthe bin weigh bar 254 by two variable forcesf, andf acting on the binweigh bar 254 on opposite sides of its fulcrum pivot and in oppositedirections about the fulcrum pivot A do not cause the bin and ice weighbars to pivot from their neutral position of FIG. 3 until the moment ofthe constant loads W, and W is overcome by the moments of the variableforces f, and f acting through their lever arms X, and X respectively.This occurs when the variable force f, equals or exceeds a predeterminedbalanced load, which for the form shown is about 4.20 pounds, or theequivalent of nineteen harvests of ice-pieces wherein each harvestweighs about one-third of a pound. Thus within the range of about 0.70pounds to 4.20 pounds the weigh bars maintain a condition of balance andthereby maintain the weigh switch in an electrically closed state. Assuccessive harvests of ice pieces are deposited in the bin the variableforce f, increases in stepped increments and is designed such that theeighteenth harvest creates a force f, of about 4.10 pounds or a loadjust below the critical unbalancing weight of 4.20 pounds with theresult that the nineteenth harvest creates a force of about 4.25 poundson the weigh rod to exceed the 4.20 pounds by a weight sufficient tocause a condition of unbalance pivoting the bin and ice weigh bars 254and 256 in unison to thelr position shown in FIG. 4 wherein ice weighbar 256 engages stop means 270 to quickly break the electricalcontinuity between post H and the ice weigh bar 256 and open the weighswitch between terminal posts A and H. The weigh switch will remain inits open position of FIG. 4 and thus prevent further ice harvests beingdeposited in the bin until a portion or all of the ice pieces areremoved therefrom and the bin returned to its inserted position.

While the embodiment of the present invention herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

I claim:

1. An automatic ice maker including a support frame, a mold pivotallysupported thereon, means for supplying liquid to said mold, means forfreezing the liquid in said mold, a drive motor, a circuit forcontrolling said drive motor, means operated by said drive motor forejecting frozen ice pieces from said mold, a collecting bin, carriermeans pivotally supported on said frame adapted to removably supportsaid bin in a position for collecting the ice pieces ejected from saidmold wherein the improvement comprises, a weigh switch in said controlcircuit, said weigh switch including an electrically conducting binweigh bar pivotally supported intermediate its ends on an electricalterminal post, said bin weigh bar having a first relatively short leverarm at one side of said terminal post and a second relatively long bincounterbalancing lever arm at the opposite side of said terminal post, aweigh rod connected to the free end of said first lever arm andextending downwardly therefrom, said weigh rod having its lower endconnected to said carrier means, said bin weigh bar being unbalancedsuch that said second lever arm tends to gravitate into contact withlower stop means supporting said bin weigh bar in a first substantiallyhorizontally disposed weigh opening position when said bin is removedfrom said carrier means, an electrically conducting ice weigh barpivotally supported adjacent its one end in spaced overlying relation tosaid bin weigh bar, said ice weigh bar pivotal support positionedoutboard of said second lever arms free end, said ice weigh bar beingunbalanced such that its free end tends to gravitate into electricalcontact with terminal stop means, said bin upon being inserted in saidcarrier means operative by means of exerting a weight on said firstlever arm for pivoting said second lever arm from its first open circuitposition to a second weigh switch closed position electricallycontacting said ice weigh bar, the weight of said ice weigh baroperative to maintain said second closed circuit position of said weighbars until a predetermined number of mold ice piece harvests have beenreceived in said bin, said bin weigh bar and said ice weigh bar beingresponsive to the weight of a final ice piece harvest to pivot said barsin unison to a third weigh switch open position, whereby said ice weighbar is moved out of electrical contact with said electrical terminalstop means and into engagement with upper stop means such that saiddrive motor is deenergized to thereby stop operation of said ice makeruntil a sufficient quantity of ice pieces have been removed from saidbin.

2. An automatic ice maker including a support frame, a mold pivotallysupported thereon, means for supplying liquid to said mold, means forfreezing the liquid in said mold, a drive motor, a circuit forcontrolling said drive motor, means operated by said drive motor forejecting frozen liquid from said mold, a collecting bin, a carrieradapted to removably support said bin in a position within the path ofmovement of the frozen liquid discharged by said ice maker, means onsaid frame pivotally supporting said carrier for movement about asubstantially horizontal axis wherein the improvement comprises, a weighswitch in said control circuit, said weigh switch including anelectrically conducting bin weigh bar pivotally supported intermediateits ends on an electrical terminal post, said bin weigh bar having afirst relatively short lever arm at one side of said terminal post and asecond relatively long bin counterbalancing lever arm at the oppositeside of said terminal post, said short lever arm having a knife-edge atits free end, a weigh rod supported on said knife-edge at its upper endand extending downwardly into supporting engagement with said carrier,lower stop means supporting said second lever arm in a firstsubstantially horizontally disposed open circuit position when said binis removed from said carrier, an electrically conducting ice weigh barpivotally supported adjacent its one end in spaced overlying relation tosaid bin weigh bar for movement in a common vertical plane with said binweigh bar, said ice weigh bar pivotal support positioned outboard ofsaid second lever arm's free end, terminal stop means supporting inelectrical conducting fashion the free end of said ice weigh bar inspaced substantially parallel relation to said bin weigh bar, said binupon being inserted in said carrier operative by means of exerting adownward force on said knife-edge for pivoting said secondcounterbalancing lever arm from its first open circuit position to asecond closed circuit position electrically contacting said ice weighbar, the weight of said ice weigh bar operative to maintain said secondclosed circuit contacting position of said weigh bars until apredetermined number of mold frozen liquid harvests have been receivedin said bin, said bin weigh bar and said ice weigh bar being responsiveto the weight of a final frozen liquid harvest to pivot said bars inunison to a third open circuit position, whereby said ice weigh bar ismoved out of electrical contact with said electrical terminal stop meansand into engagement with upper stop means to deenergize said drive motorand thereby stop operation of said ice maker until a sufficient quantityof frozen liquid has been removed from said bin.

3. An automatic ice maker including a support frame, a mold pivotallysupported thereon, means for supplying liquid to said mold, means forfreezing the liquid in said mold, a drive motor, a circuit forcontrolling said drive motor, means operated by said drive motor forejecting frozen liquid from said mold, a collecting bin, a carrieradapted to removably support said bin in a position within the path ofmovement of the frozen liquid discharged by said ice maker, said carrierpivotally supported on said frame for movement about a substantiallyhorizontal axis, said carrier being unbalanced with its forward endtending to gravitate in a downward direction, wherein the improvementcomprises, a weigh switch in said control circuit, said weigh switchincluding an electrically conducting bin weigh bar supportedintermediate its ends on an electrical terminal post for pivotalmovement in a vertical plane, said bin weigh bar having a firstrelatively short lever arm at one side of said terminal post and asecond relatively long lever arm at the opposite side of said terminalpost, said bin weigh bar being unbalanced such that said second leverarm tends to gravitate in a first direction, said short lever arm havingan upwardly and outwardly tapered knife-edge at its free end, a weighrod having a notched portion on its upper end forming a horizontallydisposed upper undercut surface supported on said knifeedge, said weighrod extending downwardly into sup porting engagement with the forwardend of said carrier, lower stop means supporting said bin weigh barsecond lever arm in a first substantially horizontally disposed opencircuit position when said bin is removed from said carrier, anelectrically conducting ice weigh bar pivotally supported adjacent itsone end in spaced overlying relation to said bin weigh bar for movementin the vertical plane of said bin weigh bar, said ice weigh bar pivotalsupport positioned outboard of said second lever arms free end such thatsaid ice weigh bar tends to gravitate in a second direction, terminalstop means positioned outboard of said knife-edge supporting inelectrical conducting fashion the free end of said ice weigh bar inspaced substantially parallel relation with said bin weigh bar, said binupon being inserted in said carrier operative by means of exerting aweight on said knife-edge for pivoting said second counterbalancinglever arm in said second direction from its first open circuit positionto a second closed circuit position electrically contacting said iceweigh bar, the weight of said ice weigh bar operative to maintain saidsecond closed circuit contacting position of said weigh bars until apredetermined number of mold frozen liquid harvests have been receivedin said bin, said bin weigh bar and said ice weigh bar being responsiveto the weight of a final frozen liquid harvest being discharged intosaid bin to pivot said bars in unison to a third open circuit position,whereby said ice weigh bar is moved out of electrical contact with saidelectrical terminal stop means and into engagement with upper stop meansto deenergize said drive motor and thereby stop operation of said icemaker until a sufficient quantity of frozen liquid has been removed fromsaid bin.

4. The automatic ice maker as claimed in claim 11 wherein the effectivelength of said relatively long lever arm is of the order of fifteentimes the effective length of said relatively short lever arm.

1. An automatic ice maker including a support frame, a mold pivotallysupported thereon, means for supplying liquid to said mold, means forfreezing the liquid in said mold, a drive motor, a circuit forcontrolling said drive motor, means operated by said drive motor forejecting frozen ice pieces from said mold, a collecting bin, carriermeans pivotally supported on said frame adapted to removably supportsaid bin in a position for collecting the ice pieces ejected from saidmold wherein the improvement comprises, a weigh switch in said controlcircuit, said weigh switch including an electrically conducting binweigh bar pivotally supported intermediate its ends on an electricalterminal post, said bin weigh bar having a first relatively short leverarm at one side of said terminal post and a second relatively long bincounterbalancing lever arm at the opposite side of said terminal post, aweigh rod connected to the free end of said first lever arm andextending downwardly therefrom, said weigh rod having its lower endconnected to said carrier means, said bin weigh bar being unbalancedsuch that said second lever arm tends to gravitate into contact withlower stop means supporting said bin weigh bar in a first substantiallyhorizontally disposed weigh opening position when said bin is removedfrom said carrier means, an electrically conducting ice weigh barpivotally supported adjacent its one end in spaced overlying relation tosaid bin weigh bar, said ice weigh bar pivotal support positionedoutboard of said second lever arm''s free end, said ice weigh bar beingunbalanced such that its free end tends to gravitate into electricalcontact with terminal stop means, said bin upon being inserted in saidcarrier means operative by means of exerting a weight on said firstlever arm for pivoting said second lever arm from its first open circuitposition to a second weigh switch closed position electricallycontacting said ice weigh bar, the weight of said ice weigh baroperative to maintain said second closed circuit position of said weighbars until a predetermined number of mold ice piece harvests have beenreceived in said bin, said bin weigh bar and said ice weigh bar beingresponsive to the weight of a final ice piece harvest to pivot said barsin unison to a third weigh switch open position, whereby said ice weighbar is moved out of electrical contact with said electrical terminalstop means and into engagement with upper stop means such that saiddrive motor is deenergized to thereby stop operation of said ice makeruntil a sufficient quantity of ice pieces have been removed from saidbin.
 2. An automatic ice maker including a support frame, a moldpivotally supported thereon, means for supplying liquid to said mold,means for freezing the liquid in said mold, a drive motor, a circuit forcontrolling said drive motor, means operated by said drive motor forejecting frozen liquid from said mold, a collecting bin, a carrieradapted to removably support said bin in a position within the path ofmovement of the frozen liquid discharged by said ice maker, means onsaid frame pivotally supporting said carrier for movement about asubstantially horizontal axis wherein the improvement comprises, a weighswitch in said control circuit, said weigh switch including anelectrically conducting bin weigh bar pivotally supported intermediateits ends on an electrical terminal post, said bin weigh bar having afirst relatively short lever arm at one side of said terminal post and asecond relatively long bin counterbalancing lever arm at the oppositeside of said terminal post, said short lever arm having a knife-edge atits free end, a weigh rod supported on said knife-edge at its upper endand extending downwardly into supporting engagement with said carrier,lower stop means supporting said second lever arm in a firstsubstantially horizontally disposed open circuit position when said binis removed from said carrier, an electrically conducting ice weigh barpivotally supported adjacent its one end in spaced overlying relation tosaid bin weigh bar for movement in a common vertical plane with said binweigh bar, said ice weigh bar pivotal support positioned outboard ofsaid second lever arm''s free end, terminal stop means supporting inelectrical conducting fashion the free end of said ice weigh bar inspaced substantially parallel relation to said bin weigh bar, said binupon being inserted in said carrier operative by means of exerting adownward force on said knife-edge for pivoting said secondcounterbalancing lever arm from its first open circuit position to asecond closed circuit position electrically contacting said ice weighbar, the weight of said ice weigh bar operative to maintain said secondclosed circuit contacting position of said weigh bars until apredetermined number of mold frozen liquid harvests have been receivedin said bin, said bin weigh bar and said ice weigh bar being responsiveto the weight of a final frozen liquid harvest to pivot said bars inunison to a third open circuit position, whereby said ice weigh bar ismoved out of electrical contact with said electrical terminal stop meansand into engagement with upper stop means to deenergize said drive motorand thereby stop operation of said ice maker until a sufficient quantityof frozen liquid has been removed from said bin.
 3. An automatic icemaker including a support frame, a mold pivotally supported thereon,means for supplying liquid to said mold, means for freezing the liquidin said mold, a drive motor, a circuit for controlling said drive motor,means operated by said drive motor for ejecting frozen liquid from saidmold, a collecting bin, a carrier adapted to removably support said binin a position within the path of movement of the frozen liquiddischarged by said ice maker, said carrier pivotally supported on saidframe for movement about a substantially horizontal axis, said carrierbeing unbalanced with its forward end tending to gravitate in a downwarddirection, wherein the improvement comprises, a weigh switch in saidcontrol circuit, said weigh switch including an electrically conductingbin weigh bar supported intermediate its ends on an electrical terminalpost for pivotal movement in a vertical plane, said bin weigh bar havinga first relatively short lever arm at one side of said terminal post anda second relatively long lever arm at the opposite side of said terminalpost, said bin weigh bar being unbalanced such that said second leverarm tends to gravitate in a first direction, said short lever arm havingan upwardly and outwardly tapered knife-edge at its free end, a weighrod having a notched portion on its upper end forming a horizontallydisposed upper undercut surface supported on said knife-edge, said weighrod extending downwardly into supporting engagement with the forward endof said carrier, lower stop means supporting said bin weigh bar secondlever arm in a first substantially horizontally disposed open circuitposition when said bin is removed from said carrier, an electricallyconducting ice weigh bar pivotally supported adjacent its one end inspaced overlying relation to said bin weigh bar for movement in thevertical plane of said bin weigh bar, said ice weigh bar pivotal supportpositioned outboard of said second lever arm''s free end such that saidice weigh bar tends to gravitate in a second direction, terminal stopmeans positioned outboard of said knife-edge supporting in electricalconducting fashion the free end of said ice weigh bar in spacedsubstantially parallel relation with said bin weigh bar, said bin uponbeing inserted in said carrier operative by means of exerting a weighton said knife-edge for pivoting said second counterbalancing lever armin said second direction from its first open circuit position to asecond closed circuit position electrically contacting said ice weighbar, the weight of said ice weigh bar operative to maintain said secondclosed circuit contacting position of said weigh bars until apredetermined number of mold frozen liquid harvests have been receivedin said bin, said bin weigh bar and said ice weigh bar being responsiveto the weight of a final frozen liquid harvest being discharged intosaid bin to pivot said bars in unison to a third open circuit position,whereby said ice weigh bar is moved out of electrical contact with saidelectrical terminal stop means and into engagement with upper stop meansto deenergize said drive motor and thereby stop operation of said icemaker until a sufficient quantity of frozen liquid has been removed fromsaid bin.
 4. The automatic ice maker as claimed in claim 1 wherein theeffective length of said relatively long lever arm is of the order offifteen times the effective length of said relatively short lever arm.